/* CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Apple-inspired System Font Stack */
:root {
    --font-system: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-mono: 'SF Mono', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
    
    /* Apple-inspired Color Palette */
    --color-primary: #007AFF;
    --color-primary-hover: #0051D5;
    --color-secondary: #5856D6;
    --color-success: #34C759;
    --color-warning: #FF9500;
    --color-danger: #FF3B30;
    
    /* Neutral Colors */
    --color-text-primary: #1C1C1E;
    --color-text-secondary: #8E8E93;
    --color-text-tertiary: #C7C7CC;
    --color-label-primary: #000000;
    --color-label-secondary: #3C3C43;
    --color-label-tertiary: #3C3C4399;
    --color-label-quaternary: #3C3C4366;
    
    /* Background Colors */
    --color-background-primary: #FFFFFF;
    --color-background-secondary: #F2F2F7;
    --color-background-tertiary: #FFFFFF;
    --color-fill-primary: #78788033;
    --color-fill-secondary: #78788028;
    --color-fill-tertiary: #7676801E;
    --color-fill-quaternary: #74748014;
    
    /* Separators */
    --color-separator: #C6C6C8;
    --color-separator-opaque: #38383A;
    
    /* Spacing System */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-xxxl: 64px;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-xxl: 20px;
    
    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-size-xs: 12px;
    --font-size-sm: 14px;
    --font-size-md: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-xxl: 24px;
    --font-size-xxxl: 32px;
    --font-size-4xl: 40px;
    --font-size-5xl: 48px;
    
    /* Line Heights */
    --line-height-tight: 1.2;
    --line-height-normal: 1.4;
    --line-height-relaxed: 1.6;
    
    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0.0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0.0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0.0, 0.2, 1);
    
    /* Z-Index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
    :root {
        --color-text-primary: #FFFFFF;
        --color-text-secondary: #8E8E93;
        --color-text-tertiary: #48484A;
        --color-label-primary: #FFFFFF;
        --color-label-secondary: #EBEBF5;
        --color-label-tertiary: #EBEBF599;
        --color-label-quaternary: #EBEBF54D;
        
        --color-background-primary: #000000;
        --color-background-secondary: #1C1C1E;
        --color-background-tertiary: #2C2C2E;
        --color-fill-primary: #7676803D;
        --color-fill-secondary: #78788033;
        --color-fill-tertiary: #7676802E;
        --color-fill-quaternary: #7676801F;
        
        --color-separator: #38383A;
        --color-separator-opaque: #C6C6C8;
    }
}

/* Base Typography */
html {
    font-size: 16px;
    line-height: var(--line-height-normal);
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

body {
    font-family: var(--font-system);
    color: var(--color-text-primary);
    background-color: var(--color-background-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

/* Skip Link for Accessibility */
.skip-link {
    position: absolute;
    top: -40px;
    left: 6px;
    background: var(--color-primary);
    color: white;
    padding: 8px;
    text-decoration: none;
    border-radius: var(--radius-sm);
    z-index: var(--z-tooltip);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 6px;
}

/* EMERGENCY FIX - FORCE HEADER VISIBILITY */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100vw;
    height: 60px;
    background: white;
    border-bottom: 1px solid #ddd;
    z-index: 9999;
    display: block;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--color-text-primary);
    font-weight: 700;
    font-size: var(--font-size-lg);
    transition: transform 0.2s ease;
    gap: 8px;
}

.logo-link:hover {
    transform: scale(1.05);
}

.logo-icon {
    width: 28px;
    height: 28px;
    color: var(--color-primary);
    flex-shrink: 0;
}

.logo-text {
    font-weight: 800;
    color: var(--color-text-primary);
}

.nav-container {
    width: 100%;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-left {
    flex: 1;
}

.nav-center {
    display: flex;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 20px;
    margin: 0;
    padding: 0;
    align-items: center;
}

.nav-link {
    color: #333;
    text-decoration: none;
    padding: 10px 15px;
    border-radius: 8px;
    font-weight: 500;
    display: flex;
    align-items: center;
    height: 40px;
}

.nav-link:hover {
    background: #f0f0f0;
}

.nav-right {
    display: flex;
    gap: 10px;
}

.search-btn, .menu-toggle {
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    border-radius: 6px;
}

.search-btn:hover, .menu-toggle:hover {
    background: #f0f0f0;
}

.search-btn svg, .menu-toggle svg {
    width: 20px;
    height: 20px;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 3px;
}

.hamburger-line {
    width: 18px;
    height: 2px;
    background: #333;
    border-radius: 1px;
}

/* MOBILE SPECIFIC */
@media (max-width: 768px) {
    .nav-center {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: white;
        border-bottom: 1px solid #ddd;
        padding: 20px;
        transform: translateY(-100%);
        transition: transform 0.3s ease;
        z-index: 9998;
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }
    
    .nav-center.mobile-open {
        transform: translateY(0);
    }
    
    .nav-links {
        flex-direction: column;
        gap: 10px;
    }
    
    .nav-link {
        display: block;
        padding: 15px;
        text-align: center;
        border: 1px solid #ddd;
        border-radius: 8px;
        background: #f9f9f9;
        color: #333;
        text-decoration: none;
        font-weight: 500;
    }
    
    .nav-link:hover {
        background: #e9e9e9;
    }
    
    .nav-link.active {
        background: #007AFF;
        color: white;
        border-color: #007AFF;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    /* Dropdown for mobile */
    .nav-dropdown .dropdown-menu {
        position: static;
        background: #f0f0f0;
        border: none;
        border-radius: 8px;
        margin-top: 10px;
        padding: 10px;
        box-shadow: none;
        max-height: 0;
        overflow: hidden;
        opacity: 0;
        transition: all 0.3s ease;
    }
    
    .nav-dropdown.active .dropdown-menu {
        max-height: 300px;
        opacity: 1;
    }
    
    .dropdown-link {
        display: block;
        padding: 10px 15px;
        color: #333;
        text-decoration: none;
        border-radius: 6px;
        margin-bottom: 5px;
        background: white;
        border: 1px solid #ddd;
    }
    
    .dropdown-link:hover {
        background: #e9e9e9;
    }
    
    .dropdown-arrow {
        width: 12px;
        height: 12px;
        transition: transform 0.3s ease;
    }
    
    .nav-dropdown.active .dropdown-arrow {
        transform: rotate(180deg);
    }
}

/* FOOTER FIX */
.footer {
    background: white;
    border-top: 1px solid #ddd;
    padding: 40px 0 20px;
    margin-top: auto;
    position: relative;
    width: 100%;
}

/* MAIN CONTENT FIX */
.main-content {
    margin-top: 60px;
    min-height: calc(100vh - 60px);
    padding-top: 20px;
}

/* Hero Section */
.hero {
    padding: var(--spacing-xxxl) 0;
    text-align: center;
    background: linear-gradient(135deg, var(--color-background-primary) 0%, var(--color-background-secondary) 100%);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.hero-title {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: var(--line-height-tight);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xxl);
    line-height: var(--line-height-relaxed);
}

/* Search Container */
.search-container {
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--color-background-primary);
    border: 2px solid var(--color-separator);
    border-radius: var(--radius-xl);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.search-box:focus-within {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.search-icon {
    width: 20px;
    height: 20px;
    color: var(--color-text-secondary);
    margin-right: var(--spacing-md);
    flex-shrink: 0;
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    background: none;
    font-size: var(--font-size-md);
    color: var(--color-text-primary);
    font-family: var(--font-system);
}

.search-input::placeholder {
    color: var(--color-text-secondary);
}

.search-submit {
    background: var(--color-primary);
    border: none;
    border-radius: var(--radius-md);
    padding: var(--spacing-sm);
    color: white;
    cursor: pointer;
    transition: background-color var(--transition-fast);
    margin-left: var(--spacing-md);
}

.search-submit:hover {
    background: var(--color-primary-hover);
}

.search-submit svg {
    width: 16px;
    height: 16px;
}

.search-hint {
    text-align: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

/* Quick Access Section */
.quick-access {
    padding: var(--spacing-xxxl) 0;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section-title {
    font-size: var(--font-size-xxxl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xxl);
    color: var(--color-text-primary);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.topic-card {
    background: var(--color-background-primary);
    border: 1px solid var(--color-separator);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-normal);
    box-shadow: var(--shadow-sm);
}

.topic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.card-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--spacing-md);
    color: var(--color-primary);
}

.card-icon svg {
    width: 100%;
    height: 100%;
}

.card-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.card-description {
    font-size: var(--font-size-md);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: var(--line-height-relaxed);
}

.card-link {
    display: inline-flex;
    align-items: center;
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

.card-link:hover {
    color: var(--color-primary-hover);
}

/* Footer - Clean White Design */
.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    position: relative;
    z-index: 2;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xxl);
}

.footer-column h3 {
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
    position: relative;
    padding-bottom: 8px;
}

.footer-column h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 3px;
    background: var(--color-primary);
    border-radius: 2px;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: var(--spacing-sm);
}

.footer-column a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 500;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-block;
    position: relative;
}

.footer-column a::before {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

.footer-column a:hover::before {
    width: 100%;
}

.footer-column a:hover {
    color: var(--color-primary);
    transform: translateX(4px);
}

.footer-bottom {
    border-top: 1px solid #e1e5e9;
    padding-top: var(--spacing-lg);
    background: #ffffff;
}

.footer-bottom-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
}

.version {
    font-family: var(--font-mono);
    background: #f3f4f6;
    color: var(--color-text-secondary);
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 12px;
}

/* Search Overlay */
.search-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: var(--z-modal);
    display: none;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.search-overlay.active {
    display: flex;
    opacity: 1;
}

.search-overlay-content {
    background: var(--color-background-primary);
    border-radius: var(--radius-xl);
    max-width: 600px;
    width: 90%;
    max-height: 80%;
    margin: auto;
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.search-overlay-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--color-separator);
}

.search-overlay-header h2 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text-primary);
}

.search-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    transition: background-color var(--transition-fast);
}

.search-close:hover {
    background-color: var(--color-fill-secondary);
}

.search-close svg {
    width: 20px;
    height: 20px;
}

.search-overlay-input {
    padding: var(--spacing-lg);
}

.search-overlay-field {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--color-separator);
    border-radius: var(--radius-lg);
    font-size: var(--font-size-md);
    font-family: var(--font-system);
    background: var(--color-background-primary);
    color: var(--color-text-primary);
    outline: none;
    transition: border-color var(--transition-fast);
}

.search-overlay-field:focus {
    border-color: var(--color-primary);
}

.search-results {
    max-height: 400px;
    overflow-y: auto;
    padding: 0 var(--spacing-lg) var(--spacing-lg);
}

/* Loading and Error states */
.loading-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xxxl);
    text-align: center;
}

.error-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xxxl);
    text-align: center;
}

.error-container h2 {
    font-size: var(--font-size-xxl);
    color: var(--color-danger);
    margin-bottom: var(--spacing-md);
}

.error-container p {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.home-content {
    text-align: center;
    padding: var(--spacing-xxxl);
}

.home-content h2 {
    font-size: var(--font-size-xxxl);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.home-content p {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
}

/* Search Results Page */
.search-results-page {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xxl) var(--spacing-md);
}

.search-results-page h1 {
    font-size: var(--font-size-xxxl);
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
}

.search-results-count {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xxl);
}

.search-results-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Print Styles */
@media print {
    .header,
    .search-overlay,
    .search-container {
        display: none;
    }
    
    .main-content {
        margin-top: 0;
    }
    
    .hero {
        page-break-after: always;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Search Section - Clean White Design */
.search-section {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 60px - 200px);
    background: #ffffff;
    position: relative;
    overflow: hidden;
    margin: 0;
    padding: 0;
}

.search-section::before {
    display: none;
}

.search-container {
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
    padding: 0 var(--spacing-md);
    position: relative;
    z-index: 2;
}

.search-logo {
    display: none;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
    background: #ffffff;
    border: 2px solid #e1e5e9;
    border-radius: 24px;
    padding: 20px 24px;
    margin-bottom: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateY(0);
}

.search-box:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border-color: #d1d5db;
}

.search-box:focus-within {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 122, 255, 0.15);
}

.search-icon {
    width: 24px;
    height: 24px;
    color: var(--color-text-secondary);
    margin-right: var(--spacing-md);
    flex-shrink: 0;
}

.search-input {
    flex: 1;
    border: none;
    outline: none;
    background: none;
    font-size: 18px;
    color: var(--color-text-primary);
    font-family: var(--font-system);
    font-weight: 500;
    line-height: 1.5;
}

.search-input::placeholder {
    color: var(--color-text-secondary);
    font-weight: 400;
}

.search-submit {
    background: var(--color-primary);
    border: none;
    border-radius: 16px;
    padding: 12px 16px;
    color: white;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    margin-left: var(--spacing-md);
    box-shadow: 0 2px 8px rgba(0, 122, 255, 0.2);
}

.search-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 122, 255, 0.3);
    background: var(--color-primary-hover);
}

.search-submit:active {
    transform: translateY(0);
}

.search-submit svg {
    width: 20px;
    height: 20px;
}

.search-hint {
    text-align: center;
    font-size: 16px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* Dropdown Navigation - Improved Arrow */
.nav-dropdown {
    position: relative;
}

.dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 4px;
    position: relative;
    color: #333;
    text-decoration: none;
    padding: 10px 15px;
    border-radius: 8px;
    font-weight: 500;
    height: 40px;
    cursor: pointer;
}

.dropdown-toggle:hover {
    background: #f0f0f0;
}

.dropdown-arrow {
    width: 12px;
    height: 12px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0.6;
    margin-left: 2px;
}

.nav-dropdown.active .dropdown-arrow {
    transform: rotate(180deg);
    opacity: 0.8;
}

.nav-dropdown.active .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0) scale(1);
}

.dropdown-menu li {
    margin: 0;
    padding: 0;
}

.dropdown-link {
    display: block;
    padding: 12px 20px;
    color: var(--color-text-primary);
    text-decoration: none;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    border-radius: 8px;
    margin: 0 8px;
}

.dropdown-link:hover::before {
    width: 100%;
}

.dropdown-link:hover {
    color: white;
    transform: translateX(4px);
    background: none;
}

/* Article Styles - Modernized */
.article {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xxl);
    background: var(--color-background-primary);
    border-radius: 20px;
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.1),
        0 4px 12px rgba(0, 0, 0, 0.05);
    margin-top: var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

.article::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--color-primary) 0%, #5856D6 100%);
}

.article-header {
    text-align: center;
    margin-bottom: var(--spacing-xxl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-separator);
}

.article-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.01em;
}

.article-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    font-weight: 500;
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

.article-content {
    font-size: 18px;
    line-height: 1.8;
    color: var(--color-text-primary);
}

.article-content p {
    margin-bottom: var(--spacing-lg);
    text-align: justify;
}

.article-content h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin: var(--spacing-xxl) 0 var(--spacing-md);
    color: var(--color-text-primary);
    position: relative;
    padding-left: var(--spacing-md);
}

.article-content h2::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(135deg, var(--color-primary) 0%, #5856D6 100%);
    border-radius: 2px;
}

.article-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: var(--spacing-xl) 0 var(--spacing-md);
    color: var(--color-text-primary);
}

.article-content ul,
.article-content ol {
    margin: var(--spacing-lg) 0;
    padding-left: var(--spacing-xl);
}

.article-content li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.article-content code {
    background: var(--color-fill-secondary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: var(--color-primary);
}

.article-content strong {
    font-weight: 700;
    color: var(--color-text-primary);
}

.article-content em {
    font-style: italic;
    color: var(--color-text-secondary);
}

/* Dropdown Menu Styles */
.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    border: 1px solid #e1e5e9;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    padding: 12px 0;
    min-width: 220px;
    opacity: 0;
    visibility: hidden;
    transform: translateX(-50%) translateY(-10px) scale(0.95);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1000;
    list-style: none;
}

.dropdown-menu::before {
    content: '';
    position: absolute;
    top: -6px;
    left: 50%;
    transform: translateX(-50%);
    width: 12px;
    height: 12px;
    background: rgba(255, 255, 255, 0.98);
    border: 1px solid #e1e5e9;
    border-bottom: none;
    border-right: none;
    border-radius: 2px 0 0 0;
    rotate: 45deg;
    backdrop-filter: blur(20px);
}

.dropdown-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 0;
    height: 100%;
    background: var(--color-primary);
    border-radius: 8px;
    transition: width 0.3s ease;
    z-index: -1;
}

@media (prefers-color-scheme: dark) {
    .dropdown-menu {
        background: rgba(28, 28, 30, 0.95);
        border: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .dropdown-menu::before {
        background: rgba(28, 28, 30, 0.95);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-bottom: none;
        border-right: none;
    }
}

/* Changelog Modal */
.changelog-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: var(--z-modal);
    display: none;
    opacity: 0;
    transition: opacity var(--transition-normal);
}

.changelog-modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 1;
}

.changelog-content {
    background: var(--color-background-primary);
    border-radius: 20px;
    max-width: 800px;
    width: 90%;
    max-height: 80vh;
    overflow: hidden;
    box-shadow: 
        0 25px 50px rgba(0, 0, 0, 0.2),
        0 10px 20px rgba(0, 0, 0, 0.1);
    transform: scale(0.9);
    transition: transform var(--transition-normal);
}

.changelog-modal.active .changelog-content {
    transform: scale(1);
}

.changelog-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-lg) var(--spacing-xl);
    border-bottom: 1px solid #e1e5e9;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
}

.changelog-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

.changelog-close {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.changelog-close:hover {
    background: #f3f4f6;
    color: var(--color-text-primary);
    transform: scale(1.1);
}

.changelog-close svg {
    width: 20px;
    height: 20px;
}

.changelog-body {
    padding: var(--spacing-xl);
    max-height: 60vh;
    overflow-y: auto;
}

.version-entry {
    margin-bottom: var(--spacing-xxl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid #f1f3f4;
}

.version-entry:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.version-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.version-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin: 0;
}

.version-date {
    background: var(--color-primary);
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.8rem;
    font-weight: 600;
}

.change-category {
    margin-bottom: var(--spacing-lg);
}

.change-category:last-child {
    margin-bottom: 0;
}

.change-category h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-sm);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.change-category ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.change-category li {
    padding: var(--spacing-sm) 0;
    padding-left: var(--spacing-lg);
    position: relative;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

.change-category li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: 700;
    font-size: 1.2em;
}

.version {
    cursor: pointer;
    transition: all 0.3s ease;
    padding: 4px 8px;
    border-radius: 6px;
    user-select: none;
}

.version:hover {
    background: rgba(0, 122, 255, 0.1);
    color: var(--color-primary);
    transform: scale(1.05);
}

/* Mobile optimizations */
@media (max-width: 768px) {
    .changelog-content {
        width: 95%;
        max-height: 85vh;
    }
    
    .changelog-header {
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    .changelog-header h2 {
        font-size: 1.25rem;
    }
    
    .changelog-body {
        padding: var(--spacing-lg);
    }
    
    .version-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .change-category h4 {
        font-size: 0.9rem;
    }
    
    .change-category li {
        font-size: 0.9rem;
        padding-left: var(--spacing-md);
    }
}

/* Hide nav-center on mobile by default */
@media (max-width: 768px) {
    .nav-center {
        display: none;
    }
}